JP2010243694A - Heat exchanger and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger stably maintaining heat exchange efficiency with a cooling liquid without filling the substantially whole of its inside with bubbles even when its attitude is varied. <P>SOLUTION: The heat exchanger 81, formed into hollow shape and containing a plurality of small flow passages Cm inside, includes: a plurality of partition walls 813 disposed in parallel with one another in the width direction of the heat exchanger 81 to form a plurality of small flow passages Cm; and an inlet part 819 and an outlet part 817 communicating the inside and the outside of the heat exchanger 81 mutually to allow the cooling liquid to flow into and out of the heat exchanger. The inlet part 819 and the outlet part 817 extend in directions opposite to each other along the width direction from a pair of center positions P1 and P2 located approximately at the centers of inner side surfaces 812A and 812B of the heat exchanger 81 in the width direction and opposed to each other, and penetrate outer side surfaces 818 and 816 of the heat exchanger. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heat exchanger that exchanges heat with a cooling liquid, and a projector including the heat exchanger.

Conventionally, in a projector, in order to efficiently cool a cooling target such as a liquid crystal panel, a circulating liquid cooling device that circulates a cooling liquid along a flow path and cools the cooling target with the circulated cooling liquid is provided. The configuration is known.
In such a liquid cooling device, in order to effectively cool the object to be cooled by the cooling liquid, a configuration using a heat exchanger that reduces the temperature of the cooling liquid is frequently used (for example, see Patent Document 1).
Specifically, the heat exchanger described in Patent Document 1 has a hollow rectangular parallelepiped shape, and an inflow portion and an outflow portion for allowing cooling liquid to flow in and out are provided on one side surface of the rectangular parallelepiped shape. The heat exchanger is formed with a water channel through which the cooling liquid flows. And the heat exchanger distribute | circulates the cooling liquid which flowed in the inside along a water channel, heat-exchanges between a cooling liquid and the partition which comprises a water channel, and reduces the temperature of a cooling liquid.

JP 2006-259282 A

By the way, in the liquid cooling apparatus as described above, bubbles are generated in the flow path as the cooling liquid evaporates due to aging. Then, when bubbles are filled and accumulated in the heat exchanger together with the cooling liquid, and the bubbles are filled over almost the entire inside of the heat exchanger, the bubbles become a heat insulating layer, so the cooling liquid and The heat exchange efficiency with the heat exchanger is reduced. That is, it is difficult to reduce the temperature of the cooling liquid.
Here, it is assumed that the heat exchanger described in Patent Document 1 projects an image from a projector in a so-called normal position (an attitude placed on an installation surface such as a desk) that projects an image in a substantially horizontal direction. It was designed as In other words, the heat exchanger is designed so that bubbles are not filled over substantially the entire interior of the heat exchanger when the projector is installed in the normal position.

For this reason, for example, in an upper projection attitude (an attitude where the projection lens is located on the upper side) for projecting an image on the upper side, or a lower projection attitude (an attitude where the projection lens is located on the lower side) for projecting an image on the lower side. When a projector is installed, there is a problem that bubbles are filled over almost the entire interior of the heat exchanger.
Specifically, in the heat exchanger described in Patent Document 1, on one side of the rectangular parallelepiped shape, the inflow portion and the outflow portion are substantially orthogonal to the projection direction, respectively, and are arranged in parallel along the projection direction. For this reason, when the projector is installed in the upper projection posture or the lower projection posture, in the heat exchanger, the inflow portion may be positioned on the upper side and the outflow portion may be positioned on the lower side.
That is, when the heat exchanger is in the above posture, the bubbles flowing into the heat exchanger together with the cooling liquid move to the upper space inside the heat exchanger, and sequentially move from the upper side to the lower side. It will be accumulated to the position of the outflow part, and bubbles will fill up substantially the whole inside the heat exchanger.
Therefore, there is a demand for a technology that can stably maintain the heat exchange efficiency between the cooling liquid and the heat exchanger without filling bubbles almost entirely inside the heat exchanger even in various postures.

  An object of the present invention is to provide a heat exchanger and a projector that can stably maintain heat exchange efficiency with a cooling liquid without bubbles being filled over substantially the entire interior even in various postures.

  The heat exchanger of the present invention is a heat exchanger that is formed in a hollow shape and has a plurality of fine flow channels therein, and is arranged in parallel along the width direction of the heat exchanger. A plurality of partition walls forming the fine flow path, and an inflow portion and an outflow portion for communicating the inside and outside of the heat exchanger and allowing the cooling liquid to flow in and out. Formed so as to extend in opposite directions along the width direction from a pair of center positions facing each other on the inner side of the exchanger in the width direction, and to penetrate to the outer side of the heat exchanger. It is characterized by being.

In the present invention, the outflow portion constituting the heat exchanger extends along the width direction from the first central position located at the approximate center in the width direction on the downstream side of the flow path on the inner surface of the heat exchanger, It is formed so as to penetrate to the outer surface of the exchanger. On the other hand, the inflow portion that constitutes the heat exchanger has an extending direction of the outflow portion along the width direction from the second central position facing the first central position on the upstream side of the flow path on the inner surface of the heat exchanger. Is formed so as to extend in the opposite direction to the outer surface of the heat exchanger.
Thus, for example, when the heat exchanger is mounted on the projector, even if the projector is installed in various postures, as shown below, bubbles are formed over substantially the entire interior of the heat exchanger. Can prevent charging.
For example, the outflow part is positioned on the top surface side of the outer casing, the inflow part is positioned on the bottom surface side of the outer casing, and the outer casing is in a posture to flow in and out the cooling liquid substantially parallel to the projection direction. A heat exchanger is arranged inside (hereinafter referred to as a first arrangement form).
When the heat exchanger is arranged in the first arrangement form, when the projector is installed in the normal orientation, the outflow part (first central position) is located on the upper side and the inflow part ( The second center position) is positioned on the lower side.
For this reason, the air bubbles that have flowed into the heat exchanger through the inflow portion move upward due to buoyancy, and are discharged to the outside together with the cooling liquid from the outflow portion located on the upper side.

In addition, when the projector is installed in the upper projection posture or the lower projection posture, the heat exchanger has a posture in which the first center position and the second center position are located at substantially the center position in the vertical direction.
For this reason, the bubbles that have flowed into the heat exchanger through the inflow portion move upward due to buoyancy, so that they are sequentially accumulated in the upper space inside the heat exchanger, and the outflow portion forming position (the first position) After being accumulated up to (1 central position), it is discharged to the outside together with the cooling liquid from the outflow portion.

From the above, even when the projector is installed in various postures, bubbles are accumulated in the heat exchanger only in the maximum half of the space inside the heat exchanger. It is possible to prevent air bubbles from being filled over substantially the entire interior.
Therefore, even when the projector is installed in various postures, the heat exchange efficiency between the cooling liquid and the heat exchanger can be stably maintained, and the temperature of the cooling liquid can be efficiently reduced to be cooled by the cooling liquid. The cooling target can be effectively cooled.

The projector of the present invention is a projector including a liquid cooling device that cools an object to be cooled with a cooling liquid, and an exterior housing that constitutes an exterior, and the liquid cooling device includes the heat exchanger described above, In the heat exchanger, the outflow portion is located on the top surface side of the exterior housing, the inflow portion is located on the bottom surface side of the exterior housing, and the cooling liquid is directed in the projection direction of the image from the projector. It is characterized in that it is arranged inside the outer casing in a posture of flowing in and out substantially in parallel.
Since the projector of the present invention includes the above-described heat exchanger and the heat exchanger is arranged in the first arrangement form, it can enjoy the same operations and effects as the above-described heat exchanger.

  The projector of the present invention is a projector including a liquid cooling device that cools an object to be cooled with a cooling liquid, and an exterior housing that constitutes an exterior, and the liquid cooling device includes the heat exchanger described above, In the heat exchanger, the height positions of the inflow portion and the outflow portion from the bottom surface portion of the outer casing are substantially the same position, and the cooling liquid flows in and out substantially parallel to the projection direction of the image from the projector. It is characterized by being disposed in the exterior casing in a posture.

In this invention, the heat exchanger is arrange | positioned as mentioned above inside an exterior housing | casing (henceforth 2nd arrangement | positioning form).
When the heat exchanger is arranged in the second arrangement form, when the projector is installed in the normal orientation, the thickness direction perpendicular to both the width direction and the extending direction of the partition wall is The posture is directed vertically.
By the way, as a heat exchanger, generally, a thickness dimension is formed so that it may become smaller than each dimension of the width direction and the extension direction of a partition.
That is, when the projector is installed in the normal orientation, the vertical gap between the space inside the heat exchanger and the hole in the outflow portion is very small.
For this reason, even if the bubbles that flow into the heat exchanger through the inflow portion move upward due to buoyancy and are sequentially accumulated in the upper space inside the heat exchanger, they are very small as described above. If it accumulates only in the space corresponding to the gap and accumulates up to the edge of the hole of the outflow part, it is discharged to the outside together with the cooling liquid through the outflow part.
In addition, when the projector is installed in the upper projection posture or the lower projection posture, the heat exchanger has the same posture as the first arrangement form.
From the above, the same operations and effects as the heat exchanger described above can be enjoyed.

1 is a diagram illustrating a schematic configuration of a projector according to a first embodiment. The figure which shows typically the structure of the liquid cooling device in 1st Embodiment. The figure which shows the structure of the optical element holding | maintenance part in 1st Embodiment. The perspective view which shows the structure of the tank in 1st Embodiment. The figure which shows the structure of the heat exchanger in 1st Embodiment. The figure which shows the structure of the heat exchanger in 1st Embodiment. The figure which shows typically the positional relationship of the projection lens and heat exchanger in 1st Embodiment. FIG. 3 is a diagram schematically illustrating various postures of the projector according to the first embodiment. The figure which shows the attitude | position of a heat exchanger in case the projector in 1st Embodiment is installed with various attitude | positions. The figure which shows typically the positional relationship of the projection lens and heat exchanger in 2nd Embodiment. The figure which shows the attitude | position of a heat exchanger when the projector in 2nd Embodiment is installed with various attitude | positions.

[First embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
[Configuration of projector]
FIG. 1 is a diagram illustrating a schematic configuration of a projector 1 according to the first embodiment. Specifically, FIG. 1 is a diagram of the internal structure of the projector 1 as viewed from the top surface portion 21 (see FIG. 8) side of the exterior housing 2.
The projector 1 forms an image according to the image information, projects it on a screen (not shown), and displays the projected image. As shown in FIG. 1, the projector 1 includes an exterior housing 2 that constitutes an exterior, an optical unit 3, a liquid cooling device 4 (see FIG. 2), and the like.

The exterior housing 2 is formed in a substantially rectangular parallelepiped shape having a top surface portion 21 (see FIG. 8) and a bottom surface portion 22 (FIG. 1) that intersect in the vertical direction when the projector is installed in a normal orientation, and has an optical inside. The unit 3 and the liquid cooling device 4 are accommodated.
In the exterior housing 2, a pair of handles 21 </ b> A (see FIG. 8) is attached to the top surface portion 21.
The pair of handles 21 </ b> A are members that are gripped by the user when carrying the projector 1, and are formed to have a substantially U-shape. The pair of handles 21A are parallel to each other, and U-shaped ends are respectively attached to the top surface portion 21 so as to extend in the front-rear direction (the direction along the projection direction of the image from the projection lens 35). ing.

The pair of handles 21 </ b> A are not specifically shown, but when the projector 1 is installed in a ceiling-suspended position (position suspended from the ceiling or the like), a plurality of screws to which ceiling-mounting brackets are attached. A hole is formed.
In other words, the projector 1 according to the present embodiment is designed so that when installed in the ceiling position, the projector 1 is in the same position as the normal position (the top surface portion 21 faces upward and the bottom surface portion 22 faces downward). Has been.

[Configuration of optical unit]
The optical unit 3 forms and projects an image according to image information under the control of a control device (not shown).
As shown in FIG. 1, the optical unit 3 includes a pair of light source devices 31A and 31B, a reflection mirror 31C, lens arrays 321, 322, a polarization conversion element 323, and an illumination optical device 32 having a superimposing lens 324. A color separation optical device 33 having dichroic mirrors 331 and 332 and reflection mirrors 333 to 336, and three liquid crystal panels 341 as light modulation elements (341R for the red light side liquid crystal panel, 341G for the green light side liquid crystal panel, 341G, A liquid crystal panel on the blue light side is assumed to be 341B), an optical device 34 having three incident-side polarizing plates 342, three emitting-side polarizing plates 343, and a cross dichroic prism 344 as a color combining optical device, and a projection optical device Projection lens 35 and optical components for housing these members 31A, 31B, 32 to 34 therein. And a body 36.

Here, as shown in FIG. 1, the pair of light source devices 31 </ b> A and 31 </ b> B has the same configuration and includes a light source lamp 311 and a reflector 312. The pair of light source devices 31A and 31B are disposed to face each other with the reflection mirror 31C interposed so as to emit a light beam toward the reflection mirror 31C.
In the optical unit 3, with the configuration described above, the light beams emitted from the pair of light source devices 31A and 31B are illuminated optical axis Ax (FIG. 1) set inside the optical component casing 36 by the reflecting mirror 31C. And is applied to the illumination optical device 32. The light beam applied to the illumination optical device 32 is made uniform in in-plane illuminance by the illumination optical device 32 and separated into three color lights of R, G, and B by the color separation optical device 33. Each separated color light is modulated by each liquid crystal panel 341 according to image information, and an image for each color light is formed. The image for each color light is synthesized by the prism 344 and projected onto a screen (not shown) by the projection lens 35.

[Configuration of liquid cooling device]
FIG. 2 is a diagram schematically showing the configuration of the liquid cooling device 4.
The liquid cooling device 4 circulates a cooling liquid such as water or ethylene glycol along an annular flow path, and cools the liquid crystal panel 341 as an optical element with the cooling liquid. As shown in FIG. 2, the liquid cooling device 4 includes three optical element holding units 5, a liquid pumping unit 6, a tank 7 as a liquid storage unit, a heat exchange unit 8, and a plurality of liquid circulation members 9. With.
The plurality of liquid circulation members 9 are constituted by tubular members that allow the cooling liquid to flow therein, and connect the members 5 to 8 to form an annular flow path.
In addition, the connection structure of each member 5-8 by the liquid circulation member 9 is mentioned later.

[Configuration of optical element holder]
FIG. 3 is a diagram showing the structure of the optical element holding unit 5. Specifically, FIG. 3 is a plan view of the optical element holding unit 5 viewed from the light beam incident side.
The three optical element holding units 5 hold the three liquid crystal panels 341, respectively, and the cooling liquid flows into and out of the three liquid crystal panels 341. The three liquid crystal panels 341 are cooled by the cooling liquid. Each optical element holding unit 5 has the same configuration, and only one optical element holding unit 5 will be described below. As shown in FIG. 3, the optical element holding unit 5 includes a liquid circulation pipe 51 and an optical element support frame 52.

The liquid circulation pipe 51 is bent so as to surround the image forming area (light transmission area) of the liquid crystal panel 341 in a plan view, and each end for allowing the cooling liquid to flow in and out is parallel to the upper side (the top surface 21 side). It is formed to extend.
Although the optical element support frame 52 is not specifically illustrated, the optical element support frame 52 has a concave portion that is recessed toward the light beam incident side corresponding to the outer shape of the liquid crystal panel 341 on the light beam emission side. 341 is stored and held.
Further, as shown in FIG. 3, an opening 521 corresponding to the image forming area of the liquid crystal panel 341 is formed at the bottom of the recess.
The optical element support frame 52 has a U-shaped through hole formed in a plan view so as to surround the recess, and a liquid flow pipe 51 is formed in the through hole. Arranged.
Although not specifically shown, the optical element support frame 52 is divided into two bodies, the light beam incident side and the light beam emission side, and is configured so as to sandwich the liquid circulation tube 51 between the two bodies. ing.
As described above, the optical element holding unit 5 is disposed so that the liquid circulation pipe 51 faces the side end of the liquid crystal panel 341, and the heat of the liquid crystal panel 341 is transferred from the liquid crystal panel 341 to the optical element support frame 52 to the liquid. The heat transfer path of the flow pipe 51 is traced to dissipate heat.

[Configuration of liquid pumping section]
The liquid pumping unit 6 is a pump that sucks and pumps the cooling liquid, and circulates the cooling liquid along an annular flow path.
The liquid pumping unit 6 has, for example, a configuration in which an impeller is disposed in a hollow member, and sucks and pumps the cooling liquid as the impeller rotates.
In addition, as a structure of the liquid pumping part 6, you may employ | adopt not only the structure which has the impeller mentioned above but the other structure using a diaphragm.

[Structure of tank]
FIG. 4 is a perspective view showing the configuration of the tank 7.
The tank 7 is composed of a substantially rectangular parallelepiped hollow member, and flows out after temporarily storing the inflowing cooling liquid.
In the tank 7, an upper end face is provided with an injecting portion 71 for injecting a cooling liquid into the tank 7, which communicates with the inside as shown in FIG. 4.
That is, after the liquid cooling device 4 is assembled, the liquid cooling device 4 is filled with the cooling liquid by injecting the cooling liquid through the injection unit 71.
Although not shown in FIG. 4, a cap for sealing the injection part 71 is attached to the injection part 71 after injecting the cooling liquid.
Further, in the tank 7, as shown in FIG. 4, an inflow port 72 and an outflow port 73 for inflowing and outflowing of the cooling liquid are provided on the two side surfaces as shown in FIG. 4.
And the tank 7 mentioned above is comprised from metal materials, such as aluminum.

[Configuration of heat exchange unit]
The heat exchange unit 8 reduces the temperature of the cooling liquid that circulates along the annular flow path. As shown in FIG. 2, the heat exchange unit 8 includes a heat exchanger 81, a partition plate 82, a Peltier element 83 as a thermoelectric conversion element, and a heat radiation side heat transfer member 84.
5 and 6 are diagrams showing the configuration of the heat exchanger 81. FIG. Specifically, FIG. 5 is a plan view of the heat exchanger 81, and FIG. 6 is a cross-sectional view taken along line VI-VI in FIG.
In the following description, for convenience of explanation, the vertical axis (Y axis), the X axis and the Z axis orthogonal to the Y axis shown in FIG.
The heat exchanger 81 has a hollow shape and exchanges heat with a cooling liquid that circulates inside. As shown in FIG. 5 or FIG. 6, the heat exchanger 81 includes an exchanger main body 81A and a shielding plate 81B.

As shown in FIG. 5 or 6, the exchanger main body 81 </ b> A is configured by a rectangular plate.
In the exchanger main body 81A, a first concave portion 811 having a substantially rectangular shape in plan view that is recessed in a concave shape is formed on the plate surface in the + X-axis direction.
In addition, a second concave portion 812 having a rectangular shape in plan view that is recessed in a concave shape is formed in the bottom portion of the first concave portion 811.
A plurality of partition walls 813 extending in the Y-axis direction and juxtaposed in the Z-axis direction (the width direction of the heat exchanger 81) are erected on the bottom portion of the second recess 812.
Note that the plurality of partition walls 813 are formed to have the same height as the depth of the second recess 812, as shown in FIG. Moreover, these partition walls 813 have a thickness dimension of about several tens of μm to several hundreds of μm, for example, and are formed with an interval of about several tens of μm to several hundreds of μm.

Further, in the side wall portion (inner side surface of the heat exchanger 81) 812A on the + Y-axis side in the second recess 812, the first central position P1 in the Z-axis direction is concave in the + Y-axis direction as shown in FIG. A recessed outflow side recess 814 is formed.
Similarly, at the second central position P2 facing the first central position P1 on the −Y-axis side wall portion (inner side surface of the heat exchanger 81) 812B in the second recess 812, as shown in FIG. An inflow-side recess 815 that is recessed in the Y-axis direction is formed.

Further, the exchanger main body 81A extends from the side wall of the outflow side recess 814 along the −Z-axis direction and penetrates to the −Z-axis side outer surface (outer surface of the heat exchanger 81) 816 and from the outer surface 816 − An outflow portion 817 that protrudes to the Z-axis side and communicates the inside of the second recess 812 and the outside of the heat exchanger 81 is formed.
Similarly, the exchanger main body 81A extends from the side wall of the inflow-side recess 815 along the + Z-axis direction and penetrates to the outer surface (the outer surface of the heat exchanger 81) 818 on the + Z-axis side and from the outer surface 818 to the + Z-axis. An inflow portion 819 that protrudes to the side and communicates with the inside of the second recess 812 and the outside of the heat exchanger 81 is formed.

As shown by a two-dot chain line in FIG. 5 or FIG. 6, the shielding plate 81 </ b> B is configured by a plate body having the same planar shape as the first recess 811, and is fitted into the first recess 811 so that the second The recess 812 is closed.
Then, by closing the second recess 812 with the shielding plate 81B, as shown in FIG. 5 or FIG. 6, a plurality of fine channels Cm in which the cooling liquid flows between the plurality of partition walls 813 are formed. . That is, the heat exchanger 81 is configured by a so-called heat exchanger such as a microchannel.
With the above configuration, as shown in FIG. 5, the cooling liquid that has flowed into the heat exchanger 81 flows in the −Z-axis direction via the inflow portion 819, flows into the second recess 812, and is on the −Y-axis side. After flowing through a plurality of fine flow paths Cm from to the + Y axis side, it flows through the outflow part 817 in the + Z axis direction and flows out of the heat exchanger 81.

The partition plate 82 is configured by a plate body having a rectangular shape in plan view, partitions the heat exchanger 81 and the heat radiation side heat transfer member 84, and integrates the heat exchanger 81, the Peltier element 83, and the heat radiation side heat transfer member 84. Turn into. The partition plate 82 is made of a material having low thermal conductivity (for example, 0.9 W / (m · K) or less).
As shown in FIG. 2, the partition plate 82 has an opening 821 that has a rectangular shape smaller than the planar shape of the heat exchanger 81 and allows the Peltier element 83 to be fitted therein.
Then, the heat exchanger 81 is provided at the peripheral portion of the opening 821 on one plate surface of the partition plate 82 so as to close the opening 821 at a substantially central region of the plate surface on the −X axis side of the exchanger main body 81A. Fixed.

Although not specifically shown, the Peltier element 83 has a plurality of junction pairs formed by joining a p-type semiconductor and an n-type semiconductor with metal pieces, and the plurality of junction pairs are electrically directly connected. It is connected to the.
In the Peltier element 83 having such a configuration, when power is supplied, as shown in FIG. 2, one end face of the Peltier element 83 becomes a heat absorbing surface 831 that absorbs heat, and the other end face dissipates heat. The heat radiating surface 832 is formed.
The Peltier element 83 is fitted into the opening 821 of the partition plate 82, and the heat absorption surface 831 is connected to the heat exchanger 81 (exchanger body 81A) so as to be able to transfer heat.

As shown in FIG. 2, the heat radiation side heat transfer member 84 is configured by a so-called heat sink having a rectangular plate body 841 and a plurality of fin members 842 protruding from the plate body 841. The heat radiation side heat transfer member 84 is fixed to the periphery of the opening 821 so as to close the opening 821 on the other plate surface of the partition plate 82. In this state, the heat radiation side heat transfer member 84 is connected to the heat radiation surface 832 of the Peltier element 83 so that heat can be transferred.
That is, in a state where the members 81, 83, 84 are integrated with the partition plate 82, a heat transfer path of the heat exchanger 81 to the Peltier element 83 to the heat radiation side heat transfer member 84 is formed.
For this reason, the heat exchanger 81 is cooled by absorbing heat from the heat absorbing surface 831 by driving the Peltier element 83. Further, the heat generated on the heat radiation surface 832 of the Peltier element 83 is radiated to the outside via the heat radiation side heat transfer member 84.

[Connection structure with liquid circulation member]
Next, the connection structure of each member 5-8 by the liquid circulation member 9 is demonstrated.
In the following, for convenience of explanation, as shown in FIG. 2, among the three optical element holding units 5, the optical element holding unit that holds the liquid crystal panel 341 </ b> R on the red light side is referred to as the red light modulation element holding unit 5 </ b> R, green. The optical element holding unit that holds the light-side liquid crystal panel 341G is referred to as a green light modulation element holding unit 5G, and the optical element holding unit that holds the blue light-side liquid crystal panel 341B is referred to as a blue light modulation element holding unit 5B.
As shown in FIG. 2, the liquid circulation member 9 is composed of six first to sixth liquid circulation members 9 </ b> A to 9 </ b> F.
Specifically, the inflow side and the outflow side of the first liquid circulation member 9A are connected to one end of each liquid circulation pipe 51 in the red light modulation element holding unit 5R and the green light modulation element holding unit 5G, respectively.
The second liquid circulation member 9B has an inflow side connected to the other end of the liquid circulation pipe 51 in the green light modulation element holding part 5G, and an outflow side of one end of the liquid circulation pipe 51 in the blue light modulation element holding part 5B. Connected to.

The third liquid circulation member 9C has an inflow side connected to the other end of the liquid circulation pipe 51 in the blue light modulation element holding unit 5B and an outflow side connected to the liquid pumping unit 6.
The fourth liquid circulation member 9 </ b> D has an inflow side and an outflow side connected to the inflow port 72 in the liquid pumping unit 6 and the tank 7, respectively.
The fifth liquid circulation member 9E is connected to the outflow port 73 in the tank 7 and the inflow portion 819 of the heat exchanger 81 on the inflow side and the outflow side, respectively.
The sixth liquid circulation member 9F is connected on the inflow side and the outflow side to the outflow part 817 of the heat exchanger 81 and the other end of the liquid circulation pipe 51 in the red light modulation element holding part 5R.

By the connection structure by the liquid circulation member 9 as described above, the red light modulation element holding unit 5R, the green light modulation element holding unit 5G, the blue light modulation element holding unit 5B, the liquid pumping unit 6, the tank 7, and the heat exchanger 81 are connected. Then, an annular flow path C returning to the red light modulation element holding portion 5R is formed again.
The liquid cooling device 4 described above cools the liquid crystal panel 341 as described below.
That is, the heat generated in the liquid crystal panel 341 is transferred to the cooling liquid via the optical element holding unit 5.
The cooling liquid flowing out of the optical element holding unit 5 follows the flow path C and flows into the heat exchanger 81.
Here, the heat exchanger 81 is cooled by absorbing heat from the heat absorption surface 831 by driving the Peltier element 83. For this reason, the cooling liquid that has flowed into the heat exchanger 81 undergoes heat exchange with the heat exchanger 81 and is cooled when it flows through the internal fine channel Cm.
Then, the cooling liquid cooled by the heat exchanger 81 flows into the optical element holding unit 5 again.

[Attitude of heat exchanger]
Next, the posture of the heat exchanger 81 when the projector 1 is installed in various postures will be described.
The positional relationship of the heat exchanger 81 with respect to the projection lens 35 is as follows.
FIG. 7 is a diagram schematically showing the positional relationship between the projection lens 35 and the heat exchanger 81. Specifically, FIG. 7 is a view as seen from the top surface 21 side.
The heat exchanger 81 is disposed inside the exterior casing 2 with the + Y-axis side facing the top surface portion 21 and the + Z-axis direction along the projection direction R of the projection lens 35.
That is, in the heat exchanger 81, the outflow portion 817 is positioned on the top surface portion 21 side, the inflow portion 819 is positioned on the bottom surface portion 22 side, and the cooling liquid flows in and out substantially parallel to the projection direction R. Arranged inside the exterior housing 2.

And the heat exchanger 81 is arrange | positioned inside the exterior housing | casing 2 as mentioned above, When the projector 1 is installed with various attitude | positions, it will become an attitude | position as shown below.
FIG. 8 is a diagram schematically illustrating various postures of the projector 1.
FIG. 9 is a cross-sectional view of the posture of the heat exchanger 81 when the projector 1 is installed in various postures as viewed from the shielding plate 81B side.
In the heat exchanger 81, when the projector 1 is installed in the normal orientation shown in FIG. 8A (the ceiling suspension posture is also the same), the outflow portion 817 (outflow side recess 814) is located on the upper side. , The inflow portion 819 (inflow side recess 815) is positioned on the lower side (FIG. 9A).
For this reason, bubbles that have flowed into the second recess 812 via the inflow portion 819 move upward due to buoyancy, and are discharged to the outside together with the cooling liquid from the outflow portion 817 located on the upper side. .

Further, the heat exchanger 81 is configured such that the projector 1 is in an upward projection posture (the posture in which the projection lens 35 is positioned on the upper side) shown in FIG. 8B or a lower projection posture (the projection lens 35 is in the lower side) shown in FIG. 9 (B) and FIG. 9 (C), the outflow side recess 814 and the inflow side recess 815 are positioned substantially at the center in the vertical direction. It becomes.
For this reason, the air bubbles that have flowed into the second recess 812 via the inflow portion 819 move upward due to buoyancy, so that they are sequentially accumulated in the upper space inside the second recess 812, and the outflow recess 814. Is accumulated from the outflow part 817 to the outside together with the cooling liquid.

The first embodiment described above has the following effects.
In the present embodiment, the outflow portion 817 and the inflow portion 819 constituting the heat exchanger 81 extend in the opposite directions along the width direction from the respective central positions P1, P2 of the side wall portions 812A, 812B, and the outer surfaces 816, 818. It is formed so as to penetrate through.
The heat exchanger 81 has an outer casing in a posture in which the outflow portion 817 is positioned on the top surface portion 21 side, the inflow portion 819 is positioned on the bottom surface portion 22 side, and the cooling liquid flows in and out along the projection direction R. 2 is disposed inside.
As a result, even when the projector 1 is installed in various postures, bubbles are accumulated in the second recess 812 only in a space that is at most approximately half of the interior of the second recess 812. It is possible to prevent air bubbles from being filled over substantially the entire interior of the two recesses 812.
Therefore, even when the projector 1 is installed in various postures, the heat exchange efficiency between the cooling liquid and the heat exchanger 81 can be stably maintained, and the temperature of the cooling liquid can be effectively reduced to reduce the temperature of the cooling liquid. The object to be cooled can be effectively cooled.

Further, the heat absorbing surface 831 of the Peltier element 83 is connected to a substantially central position of the plate surface in the exchanger main body 81A so as to be able to transfer heat. That is, when bubbles are accumulated in a substantially half space inside the second recess 812 at the maximum, a part of the endothermic surface 831 is separated from the cooling liquid via the heat exchanger 81 by the accumulated bubbles. However, the heat transfer path with the cooling liquid via the heat exchanger 81 is maintained in the other regions.
Therefore, even if bubbles are accumulated in a substantially half space inside the second recess 812 at the maximum, the cooling liquid can be sufficiently cooled by the heat transfer path.

Furthermore, since the inflow part 819 and the outflow part 817 are provided so as to be substantially parallel to the projection direction R, when the liquid circulation member 9 is piped, the liquid circulation member 9 is not connected to the heat exchanger 81. Therefore, it does not protrude toward the top surface portion 21 side and the bottom surface portion 22 side. That is, it is not necessary to increase the thickness dimension of the projector 1 (the dimension between the top surface portion 21 and the bottom surface portion 22) in consideration of the piping of the liquid circulation member 9 to the heat exchanger 81, and the thickness dimension of the projector 1 is reduced. can do.
In the first embodiment described above, in order to simplify the description, the posture of the projector 1 has been described by taking the three postures of the normal placement posture (ceiling suspension posture), the upper projection posture, and the lower projection posture as examples. However, the projector 1 can also be set to a tilted posture from the normal posture to the upper projection posture or the lower projection posture, and the above-described effects can be obtained even in such various postures.

[Second Embodiment]
Next, 2nd Embodiment of this invention is described based on drawing.
In the following description, the same structure and the same member as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.
FIG. 10 is a diagram schematically showing the positional relationship between the projection lens 35 and the heat exchanger 81 in the second embodiment. Specifically, FIG. 10 is a view as seen from the top surface 21 side.
In this embodiment, as shown in FIG. 10, only the arrangement position of the heat exchanger 81 is different from the first embodiment.

Specifically, as shown in FIG. 10, the heat exchanger 81 is configured so that the shielding plate 81 </ b> B (+ X axis side) faces the top surface portion 21 side, and the + Z axis direction is along the projection direction R. It is arranged.
That is, in the heat exchanger 81, the height positions of the inflow portion 819 and the outflow portion 817 from the bottom surface portion 22 are substantially the same position, and the cooling liquid flows in and out substantially parallel to the projection direction R. It is disposed inside the body 2.

Next, the attitude | position of the heat exchanger 81 of this embodiment when the projector 1 is installed with various attitude | positions is demonstrated.
FIG. 11 is a diagram illustrating the posture of the heat exchanger 81 when the projector 1 is installed in various postures.
11A to 11C, for convenience of explanation, the heat exchanger 81 is arranged on the + Y axis side (FIG. 11A) and on the shielding plate 81B side (FIGS. 11B and 11C). )) To see each.

In the heat exchanger 81, when the projector 1 is installed in the normal position shown in FIG. 8A (the same applies to the ceiling position), the shielding plate 81B is positioned on the upper side, and the thickness direction (X-axis direction) ) Will be in a vertical orientation.
Here, the heat exchanger 81 is formed so that the thickness dimension is smaller than the dimension in the other direction (Y-axis direction, Z-axis direction). That is, the gap between the shielding plate 81B and the hole 817A (FIG. 6) of the outflow portion 817 is very small.
For this reason, the air bubbles that have flowed into the second recess 812 via the inflow portion 819 move upward due to buoyancy, and are sequentially accumulated in the space on the shielding plate 81B side (upper side) inside the second recess 812. However, if it accumulates only in the space for a very small gap as described above and accumulates up to the hole 817A of the outflow portion 817, it is discharged to the outside along with the cooling liquid through the outflow portion 817.

Further, when the projector 1 is installed in the upper projection posture shown in FIG. 8B or the lower projection posture shown in FIG. 8C, the heat exchanger 81 is similar to the first embodiment. As shown in FIG. 11B and FIG. 11C, the outflow side concave portion 814 and the inflow side concave portion 815 are positioned substantially at the center in the vertical direction.
As described above, in the second embodiment described above, even when the heat exchanger 81 is provided as described above, the same effects as those in the first embodiment can be enjoyed.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
In each of the above embodiments, when the projector 1 is installed in various postures, if the first center position P1 is not located below the second center position P2 in any posture, it is different from the above embodiments. You may arrange | position the heat exchanger 81 in the exterior housing | casing 2 in the form.

In each said embodiment, the shape of the heat exchanger 81 is not restricted to the shape demonstrated in each said embodiment.
For example, the heat exchanger 81 has a rectangular shape in plan view, but is not limited thereto, and may be formed to have a circular shape in plan view. Similarly, the second recess 812 may also be formed to have a circular shape in plan view.
In each of the above embodiments, the liquid crystal panel 341 is adopted as a cooling target. A power supply device that supplies power to the elements, the components inside the projector 1, a control device that controls the liquid crystal panel 341, or the like may be the cooling target.

In the above embodiments, the arrangement order of the members 5 to 8 constituting the liquid cooling device 4 is not limited to the order described in the above embodiments, and may be arranged in other orders.
In each embodiment, three liquid crystal panels 341 are provided, but the number is not limited to three, and may be one, two, or four or more.
In each of the above embodiments, as the light modulation element, a light modulation element other than liquid crystal, such as a device using a micromirror, in addition to a transmissive or reflective liquid crystal panel may be employed.
In each of the above embodiments, only an example of a front type projector that projects from the direction of observing the screen has been described, but the present invention also applies to a rear type projector that projects from the side opposite to the direction of observing the screen. Applicable.

  The heat exchanger of the present invention can be used for a liquid cooling device mounted on a projector used in a presentation or a home theater.

  DESCRIPTION OF SYMBOLS 1 ... Projector, 2 ... Exterior housing, 4 ... Liquid cooling device, 21 ... Top surface part, 22 ... Bottom surface part, 81 ... Heat exchanger, 812A, 812B ... Side wall (inner surface), 813 ... partition wall, 816, 818 ... outer surface (outer surface), 817 ... outflow part, 819 ... inflow part, Cm ... fine flow path, P1, P2 ... center position, R ... projection direction.

Claims (3)

A heat exchanger that is formed in a hollow shape and has a plurality of fine flow channels therein,
A plurality of partition walls arranged parallel to each other along the width direction of the heat exchanger, and forming the plurality of fine flow paths;
The inside and outside of the heat exchanger communicate with each other, and include an inflow portion and an outflow portion for allowing cooling liquid to flow in and out,
The inflow part and the outflow part are:
From a pair of central positions located substantially in the center in the width direction on the inner side surface of the heat exchanger and facing each other, extend in opposite directions along the width direction so as to penetrate to the outer surface of the heat exchanger. A heat exchanger characterized by being formed respectively. A projector comprising a liquid cooling device that cools an object to be cooled with a cooling liquid, and an exterior housing that constitutes an exterior,
The liquid cooling device is
A heat exchanger according to claim 1,
The heat exchanger is
The outflow portion is located on the top surface side of the exterior housing, the inflow portion is located on the bottom surface side of the exterior housing, and the cooling liquid is substantially parallel to the projection direction of the image from the projector. A projector, wherein the projector is disposed inside the exterior casing in an inflow / outflow posture. A projector comprising a liquid cooling device that cools an object to be cooled with a cooling liquid, and an exterior housing that constitutes an exterior,
The liquid cooling device is
A heat exchanger according to claim 1,
The heat exchanger is
The height positions of the inflow portion and the outflow portion from the bottom surface portion of the outer casing are substantially the same position, and the cooling liquid flows in and out substantially parallel to the projection direction of the image from the projector. A projector characterized by being disposed inside an exterior housing.

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